(532cd) Application of Hydrophobic Alkyl Ligand on Palladium Catalyst for Direct Synthesis of Hydrogen Peroxide

Hydrogen peroxide is one of the most environmentally friendly oxidizing agents that can be used industrially since it generates only water after acting as an oxidizing agent. To produce hydrogen peroxide with this industrial value, a process called an ‘Auto-Oxidation(AO)” has already been commercialized, but there are environmental and cost problems. Therefore, a direct synthesis process capable of producing hydrogen peroxide from hydrogen and oxygen, which can replace the AO process, has been actively researched worldwide.

This direct synthesis process is currently having difficulty in commercialization due to the low purity of product peroxide compared to the existing AO process. So to improve this, many methods have been found to increase the selectivity of hydrogen peroxide by changing the type of catalyst or reaction conditions. In this case, it has been found that using hydrophobic properties improves accessibility of reactants H₂ and O₂ to active metals, and the product H₂O₂ is quickly desorbed immediately after synthesis, thereby preventing the decomposition reaction of hydrogen peroxide.

Therefore, in order to impart this hydrophobicity, Pd/SiO₂ catalysts applied with different amounts of C₁₈ alkyl ligand were synthesized, and as a result of application to the hydrogen peroxide direct synthesis reaction, it was confirmed that hydrogen peroxide synthesis activity was the highest at a certain degree of hydrophobicity. Various characterization analyses such as ICP, TEM, EA, and Calorimeter were performed for the catalyst to determine the cause of such activity improvement.